Particle-reinforced ultralight hollow Ni-P-B4C microlattice composite materials

•The hollow Ni-P-B4C microlattice material has ultra-low density.•The diamond-structured microlattice was fabricated by 3D printing.•The introduction of B4C improves the specific strength of Ni-P microlattice material.•This study could shed light on the composition design of microlattice material. The performance of lightweight porous materials is closely dependent on the structure and composition of the components. Herein we introduced boron carbide submicron particles as reinforcements and prepared the polymer/Ni-P-B4C microlattice composite materials with diamond structure by 3D printing and electroless plating technology. Upon dissolution of the polymer template, the ultralight hollow Ni-P-B4C microlattice with a density of 6.7 to 10.2 mg·cm−3 was obtained. Compression experiments showed that by introducing B4C, the specific strength of polymer/Ni-P-B4C microlattice is 1.5 times that of polymer/Ni-P microlattice, and the specific strength of hollow Ni-P-B4C microlattice is 2 times that of hollow Ni-P microlattice. The enhancement of specific strength is attributed to the load transfer between the Ni-P matrix and B4C particles, shear band strengthening effect, and the obstacle effect of grain refinement on dislocations.